Drum for burning and agglomerating



J. S. FASTING.

DRUM FOR BURNING A ND AGGLOMERATING.

APPLICATION FILED !UNE to.. 1919.

13943293 Patented Oct. s, 1921.

IIIIIIIIIIIIII IN VE /V TO!? UNITED STATES PATENT OFFICEy JOHANSIGISMUND FASTNG, OF VALBY, NEAR COPENHAGEN, DENMARK, ASSIGN R TO F. L.SMIDTH 85 CO., OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

DRUM FOB. BURNING .AND AG-GLOMERATING.

Application filed .Tune 10,

TO all 'ut/mm it' muy 0021667 Be it known that I, JOHAN ScsnoN.ihr-;rrena a subject of the King ot Denmark residing in 9 Monrads Alle,Valby, near Copenhagen, Denmark, have invented certain new and useful lmn'ovements in Drums for Burning and Agglomerating, of which thefollowing is a specification, reference being had to the acconpanyingdrawings, forming a part hereof.

This invention relates to rotary drums for lurning and agglomerating,and it has for its general purpose to increase the Capacity of outputand the working economy of such apparatus.

In rotary cement kilns for burning slurry an increased directtransmisson of heit from the products of combustion to the cement slurryunder treatment has been the principal concern of the art on the theorythat the efiiciency would be substantially proportional to such directtransmission. Accordingly, improvement in structures ,in

the interior of the kiln drum have been of such character as mightincrease the surface of" the slurry 'ather than the superficial area ofthe inner wall of the kiln. It has'now been found, however, that theCapacity and working: economy of kilns are primarily depondent upon theamount ot' hoat transmtted to the material from the inner wall orlining` of the `kiln. Another factor, however is the uniform conveying`of the material through the kiln in such maner as to maintain thematerial in what may` be termed a collective mass and without dispersionof the charge with undue agitation and whirlinp; of the finer particlesthereof. But while this uniform and steady Conveyinr of the bulk ot' thematerial through the Inill must be maintained and while the greatestpossible quantity of material. must be constantly maintained inengagement with some portion of the inner wall or lining` of the kiln,the desirability of exposing the greatest possible amount of material tothe products of combustion cannot be ignored. Accordingly; the presentinvention has. for its object to construct an improved kiln which shallinclude means effective to insure the heating of the material, primarilyby absorption of the heat from the inner wall of the kln and,secondarily by direct contact Spccifioaon oi' Letters Patent.

Patented Oct. 18, 1921.

1919. Serial No. 303,116.

with the products of conibustion, and which shall, at the same time,bring about the steady and uniform conveying of the inaterial throughthe kiln without permitting the undesirable dispersion or whirling ofthe imer particles thereoi'. In constructing,` a kiln with means toaccomplish the stated resultsinany variable' factors must be taken intoconsideration. In the first place, a kiln vares n temperature atdifferent points throughout its length to Very wide degrees.According-ly where the inner wall or lnlng;` might have its superficialarea increased at one point by structures of certain material. thismaterial could not be used at other points because of the differentthermo conditions. A ain, the material of the structures employed forincreasing the superficial area of the inner wall or lining must be ofsuch specific heat and yet of suitable conductivity in view of thecharacter of the material, its speed of travel and the temperature ot'the gases that it Will store heat and yet give it up to the materialbeing burned. Another variable factor which affects the Construction ofa kiln adapted to eftect the stated objects is the character oi' the:material to be treated. For instance, in a kiln for treating slurry thematerial is much wetter 'at one end than at the other. At the sectionwhere the material iS wet the contour of the inner wall of the mill mustbe such as to prevent undue clogging and yet at the section where thematerial is drier, the contour of the lining can be much more irregu`lar since the material will not adhore so readily to such irregularsurfacing. Another requirement to be consideed in realizing the mosteflicient action is that for-'uniform and steady conveying of thematerial in a collective mass through the drum. This conveying isbrought about most advantageously by constructing the inner wall of thekiln of such form as constantly to elevate the material and keep it inmotion.

In carrying out the objects stated the improved kiln is provided in itslining or on its interior wall with rings, segmental ribs or grooveswhich are of such material, form and relation to insure an increasedoutput of the kiln and greater economy in its op-` roo ventionalillustration off different types of wall Construction in kilus embodyingthe improvements. In the drawing- The figure is a longitudinal view inver tical section throu a kiln of improved Construction.

In the drawing the feed end of a drum is indcated at a, the sinteringzone at b, and the discharge end for the burnt material at c. in such adrum, as is well known, the hottest sections are nearest to thesintering zone. Further, the material is the wettest at the section moreremote from the sintering zone. In realizing the hereinbeiore statedobjects of the invention the drum is provided on its inner wall or inits lining with grooves or rings which will increase the superficialarea ot the inner surface of the drum so as to increase the transmissionof heatitherefrom to the material, which will still expose the greatestamount of material to the 'products of combustion and which will cause aconstantand uniform conveying of the material in a collective massthrough the drum and keep down the dispersion thereof and the whirlingofthe finer particles. lt has been found in practice that cast ironrings, such as are indicated at e, can be employed to advantage in thesection of the drum more remote from the sintering zone b, these ringsbeing capablc ot storing heat and yet transmit it to the material tobetreated. These rings when placed in a drum receivingwet slurry will bespaced suficiently to afi'ord some lateral support for the materialbetween them so as to carry the slurry well up the wall of the drumduring rotation of the latter, and

vet prevent the wet material from collecting between the rings. In thehotter sections of the drum, nearer to the sintering zone b, the castiron rings e will not stand the' heat, so the inner lining 'of the drumis formed with ribs d of any suitable material, such as ordinarilyemployed in kiln linings. These ribs (Z serve all of the purposespointed out with respect to the ribs e and, according to the degree ofdryness of the material in their sections, can be spaced closer togetherthan the rings e since the material will have less tendency to clog. Theribs d *give some lateral support to the material,

serving to Convey it constantly and uniforinly through the drum and yetmaintain it in a collective mass and minimize the dispersion or whirlingof the finer particles. ;the material passing through the drum is heatedlargely from its contact with the surface of the inner wall of the kiln,the supercial area of this surface being greatly increased by the ribs dand e.

. claim as my invention:

l. In a rotary kiln, heat storing and heat transmitting devicespossessing different heat storing and heat transmittng propertiescarried with the inner wall of the drum and extending generally at rightangles to the direction of travel of the material to be treated and tothe products of i combustion and spaced with relation to each other andafiording some lateral support to said material.

2. In a drum for burning, and agglomerating, having a feed endand adischarge end with a sintering zone therebetween, rings of metal capableof storing and transmit- 'ting heat supported on the lining adjacent tothe feed end and remote from the sintering zone and extending generallyat right angles to the direction of travel of the material and spaced toafiord some lateral support for the material while transmitting heatthereto, and additional ribs of heat resistant material adjacent to thesintering zone and spaced to aii'ord lateral support for the materialwhile transmitting heat thereto. This specificaton signed and witnessedthis Seventh da of April A. D. 1919.

JOI-IAN IGISMUND FASTING; Signed in the presence of:

M. TREVELT, e EWERE L. Kon.

